Starter gearing for internal combustion engines



y 1953 J. J. SABATlNl 2,841,988

STARTER GEARING FOR INTERNAL COMBUSTION ENGINES Filed Feb. 15, 1956 i 7 52 as a 16 1a 12 I INVENTOR. dmd 6 amma-:88

WITNESS United States Patent STARTER GEARING FOR INTERNAL COMBUSTION ENGINES John J. Sabatini, Horseheads, N. Y., assignor to Bendix Aviation Corporation, a corporation of Delaware Application February 13, 1956, Serial No. 564,907 6 Claims. c1. 74-6) The present invention relates to starter gearing for internal combustion engines and more particularly to that type in which a motor driven pinion is shifted manually or electromagnetically into and out of engagement with a gear of the engine to be started.

It is an object of the present invention to provide a novel gear shift of this type incorporating means for indexing the pinion on its shaft in case of tooth abutment with the engine gear during the meshing movement of the pinion.

It is another object to provide such a device in which the indexing means for the pinion is arranged to assist the meshing movement of the pinion when the abutting condition has been overcome.

It is another object to provide such a device including further a yielding coupling and an overrunning clutch connecting the pinion to the motor shaft.

Further objects and advantages will be apparent from v the following description taken in connection with the accompanying drawing in which:

Fig. 1 is a side elevation, partly broken away and in section, of a preferred embodiment of the invention showing the parts in normal or idle position.

Fig. 2 is a similar view showing the parts in cranking position; and

Fig, 3 is a similar view showing the positions of the parts in case of tooth abutment during the meshing movement of the pinion with the engine gear.

In Fig. l of the drawing there is illustrated a motor shaft 1 on which a driving and shifting sleeve 2 is slidably splined. The shaft 1 is formed with a smooth reduced portion 3 beyond the splined portion, and a coupling member 4 is slidably journalled on said smooth portion and formed with inclined coupling teeth 5 engaging with similar teeth 6 on the end of the sleeve 2.

A hollow shaft 7 is also slidably journalled on the smooth portion 3 of the motor shaft and is formed with overrunning clutch teeth 8 cooperating with similar clutch teeth 9 on the coupling member 4.

A barrel member 11 is arranged to surround the coupling member 4 and the adjacent ends of the shifting sleeve 2 and hollow shaft 7, and is connected to the hollow shaft by means of a, terminal flange 12 which engages a radial flange 13 on the end of said hollow shaft.

Means for yieldably resisting separation of the shifting sleeve 2 and coupling member 4 is provided comprising a compression spring in the form of a plurality of spring discs 14 bearing at one end against a terminal flange 18 on the shifting sleeve 2, and on the other end against a thrust washer 16 which is retained in the barrel member 11 by a lock ring 17.

Expansion of the spring 14 is limited by an internal shoulder in the barrel member 11 whereby the coupling member 4 is permitted sufiicient longitudinal movement to shuttle in and out of its clutching engagement with the hollow shaft 7. A light clutch spring 19 located between the flange 18 of the shifting sleeve and a flange ice- 21 on the coupling member 4 presses the coupling mem ber toward said hollow shaft.

A pinion 22 is spirally splined on the hollow shaft 7 and is urged against a stop nut 23 thereon by means of a mesh enforcing spring 24 located between the pinion and a shoulder 25 on'the barrel member 11.

Means is provided for shifting the sleeve 2 on the motor shaft 1 to thereby move the pinion 22 into and out of engagement with an engine gear 26. As here shown this'means comprises a collar27held by a lock ring 28 against a spacing thimble 29 which bears against a thrust ring 31 seated in a groove in the sleeve 2 in position to normally engage the thrust washer 16. A fork member 32 which may be actuated manually or electromagnetically, serves to impart longitudinal movement to the collar 27.

In operation, starting with the parts in the positions illustrated in Fig. 1, shifting movement of the fork 32 to the right is transmitted through the collar 27, thimble 29 and thrust ring 31 to the sleeve 2, and through the coupling member 4 to the hollow shaft 7, and through spring 14, barrel member 11 and meshing spring 24, to carry the pinion 22 into engagement with the engine gear 26.

If the teeth of the pinion are properly registered with the tooth spaces of the engine gear, the pinion enters into full mesh as shown in Fig. 2, and when the starting motor is energized, rotation of the motor shaft 1 is transmitted from the sleeve 2 to the coupling member 4 by means of the inclined teeth 6, 5 and from the coupling member 4 through the overrunning clutch teeth 9, 8 to the hollow shaft 7. Since the pinion 22 is seated against the stop nut 23, the rotation of the hollow sleeve is transmitted to the pinion to crank the engine.

The cranking torque tends to cause the coupling teeth 6, 5 to wedge apart as illustrated in Fig. 2, and if the initial torque is sufficient, the spring 14 may be compressed to such an extent as to permit momentary slippage to take place. Thereafter cranking torque is transmitted without slippage, the overrunning clutch teeth 9, 8 being firmly compressed together by the wedging action of the coupling teeth 6, 5.

Should the teeth of the pinion 22 abut against the teeth of the engine gear in the meshing operation as shown in Fig. 3, the longitudinal movement of the pinion is arrested, whereby the spiral splines of the hollow shaft 7 index the pinion in a forward direction to secure proper registry with the tooth spaces of the engine gear. When this happens, the mesh enforcing spring 24 urges the pinion into mesh with the engine gear, such movement being assisted by the longitudinal component of the force exerted on the pinion by the threads of the hollow shaft 7 when the starting motor is energized.

When the engine starts, the hollow shaft 7 is free to overrun the coupling member 4 by compression of the clutch spring 19, and thereafter the pinion is withdrawn in the usual manner by retraction of the shifting fork 32.

Although but one embodiment of the invention has been shown and described in detail it will be understood that changes may be made in the precise form and arrangemesh with a gear of the engine to be started.

' 2. Starter gearing as set forth in claim 1 in which the pinion is spirally splined on the hollow shaft, and including further means limiting the travel of the pinion on said hollow shaft.

3. Starter gearing as set forth in claim 1 in which the driving andshifting sleeveand the coupling member are provided with interengaging inclined coupling teeth, and thecoupling member and hollow shaft are provided with cooperating overrunning clutch teeth, and including means for yieldingly resisting separation of the shifting sleeve and coupling member.

4. Starter gearing as set forth in claim 3 in which the means for resisting separation of the shifting sleeve and coupling member comprises a barrel member connected 'to the hollow shaft, and a coupling spring connecting the barrel member to the shifting sleeve.

5. Starter gearing as set forth in claim 4 including r V 4 further means for so confining said coupling spring as to normally permit the coupling member to shuttle into and out of clutching engagement with the hollow sleeve, and including further a clutch spring urging the coupling member into engagement with the hollow shaft.

6. Starter gearing as set forth in claim 4 in which the pinion is spirally splined on the hollow shaft, and the means for transmitting axial movement to the pinion comprises a compression spring between the pinion and the barrel member, and including further an abutment on the hollow shaft for limiting the travel of the pinion thereon.

References Cited in the file of this patent UNITED STATES PATENTS 2,487,579 Miller Nov. 8, 1949 2,593,167 Miller Apr. 15, 1952 2,745,289 Miller May 15, 1956 

